1. Field of the Invention
The present invention relates to a color filter panel, an organic light emitting display (OLED) apparatus having the color filter panel and a method of manufacturing the OLED apparatus.
2. Description of the Related Art
A display apparatus that incorporates a light-emitting device having a light emitting layer interposed between a pair of electrodes has a wide viewing angle and a good display quality. Thus, this type of display apparatus is getting increasing attention as a high-quality display apparatus.
A light emitting mechanism of the light-emitting device often involves combination of holes and electrons. Holes, which correspond to positive charges, are injected into an anode and combined with electrons that are injected into a cathode to form excitons. When the excitons in high-energy state come back to ground energy state, light is generated. The above-described mechanism is commonly referred to as “electro-luminescence.”
Electro-luminescence includes fluorescence and phosphorescence. Fluorescence corresponds to a transition from a singlet state to a ground state, and phosphorescence corresponds to a transition from a triplet state to a ground state. The luminance level of electro-luminescence ranges from about thousands of cd/cm2 to about tens of thousands of cd/cm2. Due to this good brightness, using electro-luminescence for a display apparatus has been considered.
The light-emitting layer has a thickness of less than about 1 μm. Furthermore, the light-emitting layer (such as in an OLED) emits a light on its own. Therefore, an OLED apparatus may be thinner and lighter than a liquid crystal display apparatus that does not emit light on its own. While a liquid crystal display apparatus requires a backlight assembly to supply the light, the OLED apparatus does not include a backlight assembly.
Furthermore, the OLED apparatus may employ an active matrix driving method. According to the active matrix driving method, each pixel of the OLED apparatus employs a thin film transistor (TFT) so that the OLED apparatus controls each pixel. This active matrix driving method allows the OLED device to produce high-quality images with no or almost no crosstalk.
In order to display full color, the OLED apparatus may employ one of the following three coloring methods: an RGB light independently emitting type method, a color converting type method, and a color filter type method.
According to the RGB light independently emitting type method, a red light, a green light and a blue light are generated independently from a red light emitting layer, a green light emitting layer and a blue light-emitting layer, respectively.
According to the color converting type method, a blue light is generated from a blue light-emitting layer, and the blue light generated from the blue light-emitting layer is converted into other colors by a color-converting layer that is interposed between the blue light emitting layer and a substrate.
According to the color filter type method, a white light is generated from a light emitting layer, and a red color filter, a green color filter and a blue color filter are disposed between the light emitting layer and a substrate.
According to the RGB light independently emitting type method, the red light emitting layer, the green light emitting layer and the blue light-emitting layer are deposited and patterned independently. However, according to the color filter type method, the color filters are formed through photolithography. Therefore, the color filter type method may obtain higher resolution than that the RGB light independently emitting type method. However, luminance of a light decreases as it passes through the color filters. Therefore, luminance of the color filter type method is lower than that of the RGB light independently emitting type method.
Furthermore, when the color filter type method is applied to a bottom emission type OLED apparatus, a stability caused by encapsulation and a degree of freedom of manufacturing process are high, whereas an opening ratio is reduced to lower luminance. Therefore, when a resolution of the bottom emission type OLED apparatus increases, the luminance of the bottom emission type OLED apparatus is greatly decreased.